Electric cable



April 1947- D. R. sfsvsus ELECTRIC CABLE Filed April 4, 1944 MA Tin/A1.

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B; A d ager 1'0 I I Patented Apr. 15, ,1947

ELECTRIC CABLE Donald R. Stevens, Rldgewood, N. J., asslgnor to The Okonite-Callander Cable Company, Incorporated, Paterson, N. 1., a corporation of New Jersey Application April 4, 1944, Serial No. 529,468

4 Claims.

This invention is directed to an improved construction in electric cables, the conductor of which may be insulated with rubber, rubber-like materials, oil-impregnated insulation paper, in fact with any suitable insulation.

One of the objects of my invention i the provision of an electric cable provided with a new type of non-metallic outer sheath which is exceedingly strong mechanically, light in weight, waterproof and corrosion-proof where necessary, non-electrically conducting, etc., and which can be handled by the same equipment as now employed in electric cable manufacture. This sheath may be applied directly about the insulation or it may be applied about the usual cable sheath, whether the same is metallic or nonmetallic.

More specifically the present invention comprehends the employment of plywood as an outer sheath or covering for electric cables, such materials possessing the characteristics above referred to and which are advantageous to a marked degree in this industry.

My invention may take various forms and for purposes of illustration several embodiments of the invention have been illustrated in the accompanying drawing, in which:

Fig. l is a view in perspective of one embodiment of my invention; and

Figs. 2 and 3 are similar views of two other embodiments.

Referring to Fig. 1 of the drawing: 2 designates a cable conductor, which for illustrative purposes I have shown as of .the stranded type, it being distinctly understood that the conductor may be of any other type desired. In this illustration I have shown the conductor insulated with rubber or rubber-like material which has beendesignated 4.

About the insulation is a cushioning layer or wall of jute, designated 6, and immediately about this jute wall is wrapped. a plywood tape 8. The tape is wound helically about the jute 6 in much the same fashion as paper tape insulation is applied to cable conductors in this industry. The

' plywood tape, it will be appreciated, protects the rubber insulation against mechanical injury, while the jute layer 6 between the plywood tape and the rubber insulation functions as a cushion, further to protect the cable against injury. As above pointed out, in some instances the cushioning layer 6 may be omitted and the plywood tape applied directly about the insulation 4.

The plywood tape can be made by any of the accepted commercial methods so as to be inherently flexible and may be impregnated to render it highly water and moisture resistant. While such a tape is fire resistant to a consid erable degree, fire hazard can be further reduced by treating the tape with any well known fireprooflng impregnant, many of which are availablein the open market. Thermosetting as well as thermoplastic adhesives are employed in the manufacture of plywoods, and in this connection I prefer the thermosetting adhesive inasmuch as under some conditions it would be possible to apply the tape to the cable before the adhesive has been cured, and then cure in situ.

In the embodiment of my invention illustrated in Fig. 2: The cable conductor is designated 2 and in this instance is insulated with oil impregnated paper or similar insulation In. About the insulation I0 I have shown a lead sheath I! about which I apply two plywood tapes l4 and I6. These tapes may be similar to the tape 8' in Fig. 1, and are wrapped helically about the sheath l2. It is preferable to wrap them as shown, namely, in the same direction and so that one tape will break joints with the other. While this construction, as will be appreciated, protects,

the metal sheath against injury, it will be appreciated that if desired the metal sheath can be eliminated and the tape applied directly about the insulation.

In Fig. 3 I show a form of cable similar to that in Fig. 2, in that I provide a conductor 2, insulation l0 and sheath l2, about which I closely wind 9. plywood rod wrapping l8 instead of the plywood tape which is employed in Figs. 1 and 2.

In all three embodiments of the invention I have provided, as will be apparent, an outer nonmetallic sheath possessing many advantages over the constructions heretofore employed. For example, in the type of cable illustrated in Fig. 1 it is customary to employ a lead sheath or a braid sheath on the exterior of the cable. The braided sheath is expensive while the lead is not only expensive but heavy as compared with my construction. In the type of cable illustrated in Fig. 2 it is customary either to wrap the lead sheath with metal armor or to omit the armoring entirely, the lead directly contacting the ground. By applying plywood tape about the lead a nonconducting sheath is provided for the cable so that electrolysis problems are avoided. On the other hand, the lead sheath may be eliminated entirely and substituted by the plywood tapes in which event electrolysis is no longer a factor to be taken into consideration.

In Fig. 3 I also eliminate electrolysis problems by the employment of the plywood rod covering l8.

It is to be understood that changes may be made in the details of construction and arrangement of parts hereinabove described within the purview of my invention.

What I claim is:

1. A flexible electric cable comprising in combination an insulated conductor enclosed in an outer sheath of plywood tape wrapped directly about the insulation.

2. A flexible electric cable comprising in combination an insulated conductor enclosed in an outer sheath of plywood tape wrapped directly about the insulation, said sheath being impregnated to render it highly water and moisture resistant.

3. A flexible electric cable comprising in combination a rubber insulated conductor and an outer enclosing sheath of plywood tape wrapped directly about the insulation.-

4 4. A flexible electric cable comprising in com- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 328,012 Cox Oct. 13, 1885 2,149,771 Hunter Mar. '7, 1939 2,296,781 Farny Sept. 22, 1942 2,286,826 Morrison June 16, 1942 1,876,350 Schneider et a1 Sept. 6, 1932 

